But founder and CEO Will Ahmed says the company’s technology—a wrist-worn strap that measures certain biometrics 24 hours a day and sends the information to an online database for analysis—could have wider appeal.

“Going forward, we have a huge opportunity to own this concept of performance lifestyle,” Ahmed says in an interview. “What sorts of things can you change about your lifestyle or your behavior to ultimately perform at a higher level? That applies to the best athletes in the world, and eventually that applies to everyone else.”

Whoop will start selling its products to a broader population at some point in the future, Ahmed says, declining to speculate when. It will likely expand first to people whom Ahmed calls “prosumers”—former professional athletes and those who consider exercise a hobby. He thinks wearable fitness-tracking devices currently on the market are not properly serving those groups.

Whoop is collecting data on how the body recovers from exercise and monitoring how the heart rate fluctuates, among other measurements. Those are two features that Ahmed thinks will help the company stand out in a crowded sector. “Variance in the heart rate is sort of the key into your central nervous system,” he says.

Whoop has much to prove, but it has already raised about $22 million from investors and amassed an early group of high-profile users, including athletes across virtually all major U.S. professional sports leagues and college sports conferences, as well as several Olympic teams.

The Series B round announced Tuesday will go toward sales and marketing and product development. Whoop is also growing its team of 38 to around 50, Ahmed says. (For more details on the funding, see our earlier story.)

Ahmed says Whoop’s current users are a mix of paying customers and pilot testers, although he declines to say how much revenue the company has generated so far. The price of the Whoop system varies from $500 to $5,000 per athlete per year, depending on the features or services customers choose, Ahmed says.

Ahmed came up with the idea for Whoop while studying government and economics at Harvard University, where he was the captain of the men’s varsity squash team. He founded the company in 2012 with fellow Harvard students John Capodilupo, a mathematician and son of physiologists, and Aurelian Nicolae, a mechanical engineer and 3D printing expert.

Whoop worked out of the Harvard Innovation Lab for 18 months before moving into an office in Boston’s Fenway neighborhood, Ahmed says.

I was curious where the company’s name comes from—it was originally called Bobo Analytics (which itself is probably worthy of a story). Ahmed says “whoop” was an expression that he and his friends used during college. “So, people would say, ‘Hey, you fired up for the match, you got whoop?’ Or, ‘Are you going out tonight? What are your whoop levels?’” Ahmed says. “It was sort of this fun word that made people smile … and also had some link to how energetic or how good you felt.”